Log more information about why compaction can not be planned (#5532)

* Log more information about why compaction can not be planned

For the case when a tablet has more than tablet.file.max files and a
compaction can not be planned, log more information about what went into
the planning process.

* fix javadoc

Author: keith-turner

core/src/main/java/org/apache/accumulo/core/spi/compaction/CompactionPlanner.java

@@ -26,6 +26,7 @@
 import org.apache.accumulo.core.client.admin.compaction.CompactableFile;
 import org.apache.accumulo.core.data.NamespaceId;
 import org.apache.accumulo.core.data.TableId;
+import org.apache.accumulo.core.data.TabletId;
 import org.apache.accumulo.core.spi.common.ServiceEnvironment;
 
 /**
@@ -94,6 +95,12 @@ public interface PlanningParameters {
      */
     TableId getTableId();
 
+    /**
+     * @return the tablet for which a compaction is being planned
+     * @since 2.1.4
+     */
+    TabletId getTabletId();
+
     ServiceEnvironment getServiceEnvironment();
 
     CompactionKind getKind();

core/src/main/java/org/apache/accumulo/core/spi/compaction/DefaultCompactionPlanner.java

@@ -28,12 +28,14 @@
 import java.util.List;
 import java.util.Objects;
 import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.apache.accumulo.core.client.TableNotFoundException;
 import org.apache.accumulo.core.client.admin.compaction.CompactableFile;
 import org.apache.accumulo.core.conf.ConfigurationTypeHelper;
 import org.apache.accumulo.core.conf.Property;
 import org.apache.accumulo.core.spi.common.ServiceEnvironment;
+import org.apache.accumulo.core.util.NumUtil;
 import org.apache.accumulo.core.util.compaction.CompactionJobPrioritizer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -402,18 +404,34 @@ private Collection<CompactableFile> findFilesToCompactWithLowerRatio(PlanningPar
     }
 
     if (found.isEmpty() && lowRatio == 1.0) {
-      // in this case the data must be really skewed, operator intervention may be needed.
+      var examinedFiles = sortAndLimitByMaxSize(candidates, maxSizeToCompact);
+      var excludedBecauseMaxSize = candidates.size() - examinedFiles.size();
+      var tabletId = params.getTabletId();
+
       log.warn(
-          "Attempted to lower compaction ration from {} to {} for {} because there are {} files "
-              + "and the max tablet files is {}, however no set of files to compact were found.",
-          params.getRatio(), highRatio, params.getTableId(), params.getCandidates().size(),
-          maxTabletFiles);
+          "Unable to plan compaction for {} that has too many files. {}:{} num_files:{} "
+              + "excluded_large_files:{} max_compaction_size:{} ratio_search_range:{},{} ",
+          tabletId, Property.TABLE_FILE_MAX.getKey(), maxTabletFiles, candidates.size(),
+          excludedBecauseMaxSize, NumUtil.bigNumberForSize(maxSizeToCompact), highRatio,
+          params.getRatio());
+      if (log.isDebugEnabled()) {
+        var sizesOfExamined = examinedFiles.stream()
+            .map(compactableFile -> NumUtil.bigNumberForSize(compactableFile.getEstimatedSize()))
+            .collect(Collectors.toList());
+        HashSet<CompactableFile> excludedFiles = new HashSet<>(candidates);
+        examinedFiles.forEach(excludedFiles::remove);
+        var sizesOfExcluded = excludedFiles.stream()
+            .map(compactableFile -> NumUtil.bigNumberForSize(compactableFile.getEstimatedSize()))
+            .collect(Collectors.toList());
+        log.debug("Failed planning details for {} examined_file_sizes:{} excluded_file_sizes:{}",
+            tabletId, sizesOfExamined, sizesOfExcluded);
+      }
     }
 
     log.info(
         "For {} found {} files to compact lowering compaction ratio from {} to {} because the tablet "
             + "exceeded {} files, it had {}",
-        params.getTableId(), found.size(), params.getRatio(), lowRatio, maxTabletFiles,
+        params.getTabletId(), found.size(), params.getRatio(), lowRatio, maxTabletFiles,
         params.getCandidates().size());
 
     return found;
@@ -482,15 +500,18 @@ private Set<CompactableFile> getExpected(Collection<CompactionJob> compacting) {
     return sortedFiles.subList(0, numToCompact);
   }
 
-  static Collection<CompactableFile> findDataFilesToCompact(Set<CompactableFile> files,
-      double ratio, int maxFilesToCompact, long maxSizeToCompact) {
-    if (files.size() <= 1) {
-      return Collections.emptySet();
-    }
-
+  /**
+   * @return a list of the smallest files where the sum of the sizes is less than maxSizeToCompact
+   */
+  static List<CompactableFile> sortAndLimitByMaxSize(Set<CompactableFile> files,
+      long maxSizeToCompact) {
     // sort files from smallest to largest. So position 0 has the smallest file.
     List<CompactableFile> sortedFiles = sortByFileSize(files);
 
+    if (maxSizeToCompact == Long.MAX_VALUE) {
+      return sortedFiles;
+    }
+
     int maxSizeIndex = sortedFiles.size();
     long sum = 0;
     for (int i = 0; i < sortedFiles.size(); i++) {
@@ -502,10 +523,22 @@ static Collection<CompactableFile> findDataFilesToCompact(Set<CompactableFile> f
     }
 
     if (maxSizeIndex < sortedFiles.size()) {
-      sortedFiles = sortedFiles.subList(0, maxSizeIndex);
-      if (sortedFiles.size() <= 1) {
-        return Collections.emptySet();
-      }
+      return sortedFiles.subList(0, maxSizeIndex);
+    } else {
+      return sortedFiles;
+    }
+  }
+
+  static Collection<CompactableFile> findDataFilesToCompact(Set<CompactableFile> files,
+      double ratio, int maxFilesToCompact, long maxSizeToCompact) {
+
+    if (files.size() <= 1) {
+      return Collections.emptySet();
+    }
+
+    List<CompactableFile> sortedFiles = sortAndLimitByMaxSize(files, maxSizeToCompact);
+    if (sortedFiles.size() <= 1) {
+      return Collections.emptySet();
     }
 
     int windowStart = 0;

core/src/test/java/org/apache/accumulo/core/spi/compaction/DefaultCompactionPlannerTest.java

@@ -45,6 +45,9 @@
 import org.apache.accumulo.core.conf.SiteConfiguration;
 import org.apache.accumulo.core.data.NamespaceId;
 import org.apache.accumulo.core.data.TableId;
+import org.apache.accumulo.core.data.TabletId;
+import org.apache.accumulo.core.dataImpl.KeyExtent;
+import org.apache.accumulo.core.dataImpl.TabletIdImpl;
 import org.apache.accumulo.core.spi.common.ServiceEnvironment;
 import org.apache.accumulo.core.spi.common.ServiceEnvironment.Configuration;
 import org.apache.accumulo.core.spi.compaction.CompactionPlan.Builder;
@@ -754,6 +757,11 @@ public TableId getTableId() {
         return TableId.of("42");
       }
 
+      @Override
+      public TabletId getTabletId() {
+        return new TabletIdImpl(new KeyExtent(getTableId(), null, null));
+      }
+
       @Override
       public ServiceEnvironment getServiceEnvironment() {
         ServiceEnvironment senv = EasyMock.createMock(ServiceEnvironment.class);

core/src/test/java/org/apache/accumulo/core/util/NumUtilTest.java

@@ -27,7 +27,6 @@
 import org.junit.jupiter.api.Test;
 
 public class NumUtilTest {
-
   @Test
   public void testBigNumberForSize() {
     Locale.setDefault(Locale.US);

server/tserver/src/main/java/org/apache/accumulo/tserver/compactions/CompactionService.java

@@ -47,7 +47,9 @@
 import org.apache.accumulo.core.conf.Property;
 import org.apache.accumulo.core.data.NamespaceId;
 import org.apache.accumulo.core.data.TableId;
+import org.apache.accumulo.core.data.TabletId;
 import org.apache.accumulo.core.dataImpl.KeyExtent;
+import org.apache.accumulo.core.dataImpl.TabletIdImpl;
 import org.apache.accumulo.core.spi.common.ServiceEnvironment;
 import org.apache.accumulo.core.spi.compaction.CompactionExecutorId;
 import org.apache.accumulo.core.spi.compaction.CompactionJob;
@@ -247,6 +249,11 @@ public TableId getTableId() {
       return comp.getTableId();
     }
 
+    @Override
+    public TabletId getTabletId() {
+      return new TabletIdImpl(comp.getExtent());
+    }
+
     @Override
     public ServiceEnvironment getServiceEnvironment() {
       return senv;